Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
743 PM EDT Sat Nov 06 2021
Valid 12Z Wed Nov 10 2021 - 12Z Sun Nov 14 2021
...Overview and Model Guidance...
Model spread/differences do not appear excessive again today in
and around Alaska through the medium-range period. Much of the
model uncertainty lies well to the south of Alaska in the
northeastern Pacific where the main storm track is forecast to
stay. Towards the end of next week, models are in rather good
agreement for a cyclone to curve into the Gulf of Alaska. The 12Z
ECMWF, rather than the 00Z run, appears more compatible with the
rest of the guidance by slowing down the forward motion of this
cyclone. Therefore, a blend of the deterministic 12Z GFS, ECMWF,
and CMC together with their ensemble means was used to compose the
WPC forecasts for Alaska for Days 4-6, followed by transitioning
to mostly an even blend of the ensemble means by Day 8. Overall,
this blend yielded a solution quite compatible with yesterday's
WPC forecasts.
...Weather/Hazard Highlights...
The Alaska region should be relatively quiet in terms of impactful
precipitation and hazards through much of the medium-range period.
Dry conditions will likely prevail for the interior sections
northward to the North Slope. Meanwhile, a cyclone should be on
its demise when it gets closer to the southern tip of the
Panhandle on Wednesday. As the weekend approaches, an increasing
chance of precipitation is expected to overspread the Panhandle
where the main storm track across the northeastern Pacific
converges with the approach of a significant occluded cyclone.
The precipitation may become heavy by next Friday and into the
weekend ahead of this system along the Panhandle.
For temperatures, colder than normal conditions are expected to
persist for the central and southern portions of Alaska, with
sub-zero temperatures over the interior section. The coldest
anomaly will be found across southwestern mainland. The Alaska
Peninsula, the Panhandle, and the Aleutians will also see below
normal temperatures. Meanwhile, the North Slope will likely
experience above normal temperatures into next weekend.
Kong
Additional 3-7 Day Hazard Information can be found on the WPC
medium range hazards outlook chart at:
https://www.wpc.ncep.noaa.gov/threats/threats.php
WPC medium range Alaskan products including 500mb, surface
fronts/pressures progs and sensible weather grids can also be
found at:
https://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif
https://www.wpc.ncep.noaa.gov/alaska/akmedr.shtml
https://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html